Anahi Ametrine

| 4 min read

The whole world is littered with stark juxtapositions. Good and evil, night and day, young and old, happy and sad, rich and poor. Complimentary colours work in a similar way – these are colours that if combined create grey, black or white. Red and green are probably the most well-known pairing, but one of the pairs that is most loved by artists is the contrasting colours of yellow and purple. The colour of sunsets and sunrises, when they are used side by side, each colour brightens the other. Wouldn’t it be amazing if you could find something like that in a gemstone?

You can!

The more you learn about gemstones, the more you realise that Mother Nature can so some pretty epic stuff. One of the most ridiculously extraordinary things She’s ever come up with is Ametrine. This fascinating gem is a mixture of purple Amethyst and yellow Citrine. It can either be a 50:50 split or as a ‘Sunburst’ mix of swirling colours.


Good question! Both Amethyst and Citrine are closely related members of the Quartz family. They are both made up of silicon dioxide (SiO2), coloured by iron (Fe+++) impurities in the gem. In almost every case, mines will produce either a purple or a yellow variety of this gem. In just one mine in the world, the Anahi mine in Bolivia, this gem naturally crystallises with two colours alongside each other.

Richly colourful Ametrine

This is due to a natural heat graduation through the crystal during formation. This changes the chemical bonds between the iron impurities and the oxygen, changing their molecular structure, meaning that the gem appears yellow rather than purple. If even a little more heat had been present, the entire crystal would have formed as Citrine.

Is it unique?

Not quite. There are other gems which naturally show more than one colour. This is usually due to colour change (the ability to show a different colour in different lighting conditions), or pleochroism (the ability to show a different colour from different angles). There are very few gemstones which show both colours strongly and equally in all lighting conditions and from every angle. Ametrine is one of these, Bi-Colour Tourmaline is the other.

Gemporia CEO Steve Bennett inspecting a Bi-Colour Tourmaline specimen

Bi-Colour Tourmaline has a greater range of colour, with varieties found in combinations of pink, red, green, yellow or brown. Where Ametrine pips it to the post though, is clarity. Tourmaline is often included or cloudy, but Ametrine is found with exceptional clarity.


For a long time, Ametrine was cut in 50:50 octagon shapes, as if it was a Bi-Colour Tourmaline. Tourmaline grows in long, thin crystals (rough Tourmaline always makes me think of rhubarb!) with the colour usually in an obvious split between one end and the other, so it makes sense to cut a Bi-Colour Tourmaline in an octagon shape. Ametrine grows with the colour in zones and so cutting it as a 50:50 split is hugely wasteful.

Ametrine rough with colour zoning

More recently, people have begun to prefer less conform cuts, showing off the individual crystal’s colouring. The vividness of both colours is deemed more important than a perfect colour split down the middle of the gem. Lapidarists have also begun to play with unusual ‘sunburst’ and fancy cuts. By choosing areas where the colours naturally swirl together, a whole host of subtle hues and nuances of the two colours can be seen when looking through the finished gem.

Many cutting houses have also found that in rough Ametrine pieces without much saturation of colour, they are forced to cut the gem into baguette shapes with huge table facets, to let enough light in and give a good enough view so that what little colour split there is in the gem can be seen. Our recent Ametrine rough has been so richly coloured that we are able to cut it in a range of cuts, (unusually including princess cuts) and cut it properly, to maximise beauty and light return, while keeping the richness of colour.

Ametrine princess cut ring by Gemporia

Why we love it

This extraordinary and rare yellow and purple gemstone is one of the most unique and mesmerising gemstones ever created by Mother Nature. It is also more affordable than most people would expect of such a rare single-locational stone. Whether you’re a gem aficionado or not, this is a gem guaranteed to enthral and captivate the soul.

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